The securitization of adjustable-rate mortgages boomed to a record $721.9 billion in 2004, smashing the industry’s previous record set just the year before by a whopping 63 percent. A new market analysis and ranking by Inside MBS & ABS shows that ARM securitization hit a record high last year because volume was huge in the non-agency MBS market. A total of $537.8 billion of adjustable-rate mortgages were securitized in non-agency deals, including jumbo, subprime, Alternative…